This research proposal is designed to enable New England Medical Center to continue participation in the priamry Breast Cancer Therapy Group--NSABP. The overall specific aim of the NSABP is to improve disease free survival and survival in patients with primary operable breast and colo-rectal cancer. The Tufts University/New England Medical Center network has been an NSABP member since June 1971. Currently, 86 patients are being followed on long-term adjuvant protocols, at an annual new patient accrual rate of 28 patients per year. We expect to increase our accrual rate to approximately 38 patients per year based on the opening of NSABP breast protocols to patients who have undergone segmental mastectomy, education of surgeons regarding referral of node-negative and intraductal breast cancer patients and recent acquisition of two strong affiliate bases. The entry of these patients will enhance NSABP goals by enabling a more rapid and effective evaluation of current therapeutic regimes and will provide information for the design of future studies. Unique features of the New England Medical Center program which contribute to the overall success of NSABP include: 1) the multidisciplinary Breast Health Center 2) basic research conducted in the areas of oncogenes, 3) estrogen receptor assay research development and 4) clinical application of the role of biological response modifiers such as IL-2 and lymphokine activated cytotoxity and tuftsin and mechanisms of estrogen/tamoxofin on growth of tumor cells.